1. Field of the Invention
This invention relates to chain saw guard structures of the type which are movably mounted on the chain saw for pivotation from a guarding position near to the blade of the saw to an operating position which permits the saw blade to cut through a log or the like.
2. Brief Description of the Prior Art
Many structures have previously been manufactured and sold which are intended to function as effective guards for chain saws and are utilized with such saws to prevent injury of an operator. Such guards generally provide rigid structures which enclose the chain saw guide plate and the chain saw blade when the saw is not being used to cut through a log or other structure. Many such chain saw guards are pivotally supported at one end adjacent the chain saw housing so as to permit the guard to be pivoted to a non-interfering position at a time when the saw blade is being used to cut through a log, and to still afford some protection to the hands and arms of the user even at these times. The guard structures so provided frequently include a protective frame or housing which swings upwardly due to the displacing action of a part of the log above the lower or cutting run of the chain saw blade, with the housing or frame being pivoted further upwardly as the chain saw progresses further through the log to be cut. With some types of chain saw guards, a portion of the guard is positioned alongside the lower or bottom run of the chain saw blade to afford protection at that location. However, such lower guard structures are, for the most part, made semi-permanent in their position in relation to the chain saw blade, and thus decrease, to some extent, the facility and flexibility of operation of the chain saw.
Chain saw guard structures of the types described are depicted in U.S. Pat. No. 3,230,987 to Woleslagle; U.S. Pat. No. 2,937,673 to Duperron et al.; U.S. Pat. No. 3,380,493 to Giroux; U.S. Pat. No. 3,754,328 to Knerr; U.S. Pat. No. 3,384,136 to Marin et al.; U.S. Pat. No. 3,182,695 to Rigoni; U.S. Pat. No. 3,808,684 to Ludwig; and U.S. Pat. No. 3,059,673 to Woleslagle.
In general, guard structures for chain saws of the type described, and which have been marketed previously, while providing good protection from inadvertent injury by contact with the saw blade during its use, have failed to provide complete protection for the feet, legs, hands and arms of the user during all phases of use of the saw. Some types of guards are pivotally mounted on the housing of the saw so as to pivot to one position or another either above the saw blade or below it during use of the saw, but complete protection by the provision of a pair of completely shielding pivotal subframes which guard both the upper run and the lower run of the saw blade during all times of usage or non-usage of the saw has not been provided. Moreover, many of the types of chain saw guards previously in use have been relatively heavy in their construction, and such weight, when added to the chain saw, makes these guard structures unattractive to the user when a heavy-duty saw is employed over extended periods of usage, with little time for rest or relaxation on the part of the user. Further, some of the guard structures provided have been expensive as a result of the operating mechanism used, and the provision of a solid, completely enclosing housing which extends around a major portion of the blade and includes a substantial quantity of metal.